<template>
  <view class="cate">
    <!-- :bgcolor="'black'" :radius="10" 动态指定背景颜色和圆角-->
    <my-search @click="gotoSearch"></my-search>
    <view>
      <view class="scroll-view-container">
        <!-- 左侧的滚动视图区域 -->
        <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
          <block v-for="(item,i) in cateList" :key="i">
            <view :class="['left-scroll-view-item',i===active?'active':'']" @click="changeActive(i)">{{item.cat_name}}
            </view>
          </block>
        </scroll-view>
        <!-- 右侧的滚动视图区域 -->
        <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
          <!-- 二级分类容器 -->
          <view class="cate-lv2">
            <view v-for="(item1,i1) in cateLevel2" :key="i1">
              <!-- 二级分类标题 -->
              <view class="cate-lv2-title">/{{item1.cat_name}}/</view>
              <!-- 三级分类容器 -->
              <view class="cate-lv3-list">
                <view v-for="(item2,i2) in item1.children" :key="i2" class="cate-lv3-item"
                  @click="gotoGoodslist(item2)">
                  <image :src="item2.cat_icon"></image>
                  <text>{{item2.cat_name}}</text>
                </view>
              </view>

            </view>
          </view>
        </scroll-view>
      </view>
    </view>
  </view>
</template>

<script>
  // 导入自己封装的 mixin 模块
  import badgeMix from '@/mixins/tabbar-badge.js'
  export default {
    // 将 badgeMix 混入到当前的页面中进行使用
    mixins: [badgeMix],
    data() {
      return {
        // 窗口的可用高度 = 屏幕高度 - navigationBar高度 - tabBar 高度
        wh: 0,
        // 一级分类列表
        cateList: [],
        active: 0,
        // 二级分类
        cateLevel2: [],
        // 滚动条距离顶部距离
        scrollTop: 0
      };
    },
    onLoad() {
      // 获取当前系统的信息
      const sysInfo = uni.getSystemInfoSync()
      // 为 wh 窗口可用高度动态赋值
      this.wh = sysInfo.windowHeight;
      this.getCateList();
    },
    methods: {
      //获取一级分类列表
      async getCateList() {
        const {
          data: res
        } = await uni.$http.get('/api/public/v1/categories');
        if (res.meta.status !== 200) return uni.$showMsg;
        this.cateList = res.message;
        //显示首页二级分类
        this.cateLevel2 = res.message[0].children;

      },
      changeActive(i) {
        this.active = i;
        //根据选中的一级分类动态赋值
        this.cateLevel2 = this.cateList[i].children;
        // 让scrollTop的值在0与1变换
        this.scrollTop = this.scrollTop === 0 ? 1 : 0;
      },
      gotoGoodslist(item2) {
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item2.cat_id
        })
      },
      gotoSearch() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;

    .left-scroll-view {
      width: 120px;

      .left-scroll-view-item {
        line-height: 60px;
        background-color: #f7f7f7;
        text-align: center;
        font-size: 12px;

        // 激活项的样式
        &.active {
          background-color: #ffffff;
          position: relative;

          // 渲染激活项左侧的红色指示边线
          &::before {
            content: ' ';
            display: block;
            width: 3px;
            height: 30px;
            background-color: #c00000;
            position: absolute;
            left: 0;
            top: 50%;
            transform: translateY(-50%);
          }
        }
      }
    }
  }

  .cate-lv2-title {
    text-align: center;
    padding: 10px 0px;
    font-size: 10px;
    font-weight: bold;
  }

  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;

    .cate-lv3-item {
      display: flex;
      width: 33.3%;
      flex-direction: column;
      align-items: center;
      margin-bottom: 10px;

      image {
        width: 60px;
        height: 60px;
      }

      text {
        font-size: 12px;
      }
    }
  }
</style>